Sullivan City is a city located in Hidalgo County Texas. With a 2020 population of 4,174, it is the 412th largest city in Texas and the 5277th largest city in the United States . Sullivan City is currently growing at a rate of 0.05% annually and its population has increased by 4.30% since the most recent census, which recorded a population of 4,002 in 2010. Sullivan City reached it's highest population of 4,178 in 2016. Spanning over 4 miles, Sullivan City has a population density of 1,163 people per square mile.
The average household income in Sullivan City is $39,556 with a poverty rate of 31.66%. The median rental costs in recent years comes to $563 per month, and the median house value is $58,100. The median age in Sullivan City is 31.4 years, 35.9 years for males, and 27.8 years for females.